what kind of muffler would deliver the best gas mileage? a complete straight through design like a glasspack or something like a thrush welded?

I think they would be similar, but probably the glasspack. Im going with those thrush weldeds

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

well, right now I'm running a glasspack but will soon switch to the thrush welded as the glasspack sounds a little bit too "harsh" for my taste...

Another question just came to me, when running duals, what size is best? Dual 2" or dual 2.25"?

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

ok after shooting thru this post i have to reply.

i worked @ a shop that did nothing but awesome exhaust, weenie mufflers and cats where recycled!

i belive in a strait forward exhaust, and i have caught all kinds of hell in the past for it. but its cheaper. it has good flow and sounds massive.
others like a nice sounding exhaust and hey that's good too.

now there are kits from dimond eye that are pre-bent and all you have to do is assemble. now i DO reccomend that it be welded together, but a cheapo harbor feight mig runs around 99bux but be sure to get some anti splatter paste, cause its gonna be messy if you don't.

the frist day i met cj i had my exhaust clamped and bolted together, it worked but these things don't hold up for long. he helped me fix it and with a simple 18.00 cherry bomb my 73 sounded massive, and got better millage too!

yoru best bet is get your parts in order, pipe and what ever muffler u like.
then find a local mom and pop shop that can weld good. have them finish it off. and some shops will just do it for 50 bux providing u have all the parts pre bent and redy to go.

it takes me about 15 mins to weld up an abody exhaust if all the parts are there. and provided its on a lift.

now are you gonna go with a standard muffler ie: flowmaster or a knock off flowsound .. i like the flowsounds. or do ya wanna go glass pak.

anyways here is a few examples of diff mufflers on my darts:

glasspak and stinger, http://www.youtube.com/watch?v=GO5jzA8Tddw

dtm 111 glass pak fart can, http://www.youtube.com/watch?v=0_ZpMnSDpHc

dtm 111 with a mix of 2 1/2 and 3" pipe http://www.youtube.com/watch?v=VdoSyDEGZ9I

i love a loud exhaust, some do not! and you may not, so really think about what your car is gonna sound like cause every day you have to hear it! and a wide open 10" out side dim. ss glaspak roars. ( i have one!) but a louder car attacts attention, it makes heads turn, and girls look. but again it makes the police look also.

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"Marilyn" 64 Dart GT & "Stella" 64 Valiant V100 Sedan - 63 Norton Project

I love loud exhaust too! But glasspaks are just not my style on a slant. I want more of a deeper sound. I have a few different mufflers I want to try out. I have these summit flomaster knockoffs and I wana get two of those thrush welded mufflers. I thought about doing my own exhaust, but:
1.) I cant weld worth S**T
2.)I dont have a place to do it
3.)What kind of bends/tubes do I get and how long to get them?

But like you said, I might be able to get a local shop to do it for me. Ill look into that.

Now on to the next part of exhaust... The long debated Headers or Dutra Duals!!! I have weighed the pros and cons of both but still cannot decide!

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

I vote for the Dutra duals, Dusterguy 225. First, you list your car as a daily driver, and the Dutras are supposed to be better for cold operation and low end power. Also it would show support for the small scale fabricator/ slant six community.
I'm still wondering if there is a 2 1/4" exhaust (downtube) available for a 67 a-body, or is it a fabrication item?

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/6 '67 Barracuda convertible, electronic ignition, 4-OD, street cam, SBP KH discs, 3.55 SG 7.25" 1" t-bars. Bilstein.
340 '67 fastback, Doug Nash 5-speed.
1988 Toyota pickup work truck

If I were building a slant six exhaust system from scratch, I would go with Dutra Duals for the manifolds, 2 inch pipes leading back into a single 2 1/4 - 2 1/2 inch pipe and a Walker Quiet-Flow muffler. Lots of flow, but nice and mellow tone.

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Casually looking for a Clifford hyperpak intake for cheap.

I think im in for the Dutra Duals, but its just the modifying of the rear section that really gets me.

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'74 Duster 225 Super Six w/904
14" Cragar SS wheels

Contact Doug, he will sell you a rear section already modified. Or if you want to get spendy, a dual-dual. Userid "Doc" or "Doctor Dodge"

F-Body exhaust pipes are 2.25" and should bolt right on. They go down just like the factory pipe, but then bend toward the center of the car, and go inbetween the torque converter inspection plate, and the oil pan on the engine. Then exits on the passenger side.

You will need to make custom mounts because there are no hangers anywhere under these cars, until you get to the rear wheel wells.

I have had to put off getting my Dutras installed until I get my 2bbl intake all cleaned up and painted. I am just going to go with factory size piping for now, and upgrade to 2" later if I feel it necesary. I am going to run true Duals, with one muffler per pipe(either those Raptors I have, or some glasspacks) and have them exit the side of the car infront of the rear tire.

Should make it look nice, and sound awesome. Plus, I have drawn up some diagrams so that both the pipes will be within 2" of eachother in length. Yay!



~THOR~

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1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

F-body head pipes DO NOT work on an A-body. I have tried it. Only about the first eight inches or so will fit.

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Casually looking for a Clifford hyperpak intake for cheap.

Correct. And that's really all you need, is the flange and first 8 inches or so of 2¼" pipe. A good exhaust shop can weld from there. The tough part is making that flange and first bit of length from scratch; it's got a funny bend in it that many shops find very difficult to make.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Where does it interfere? Not disagreeing, just wondering.

~THOR~

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1984 D100 Shorty Custom
Certified Auto Appraiser - RevItUp Classic Appraisals
President - Cherry City Bombers CC
Part of Tyrde-Browne Racing

Well, if I recall correctly, the first thing it hits is the steering gearbox, and it is downhill from there since that throws the rest of it out of whack.

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Casually looking for a Clifford hyperpak intake for cheap.